The grades on a history midterm at Almond are normally distributed with $\mu = 68$ and $\sigma = 3.0$. Michael earned a $61$ on the exam. Find the z-score for Michael's exam grade. Round to two decimal places.
A z-score is defined as the number of standard deviations a specific point is away from the mean We can calculate the z-score for Michael's exam grade by subtracting the mean $(\mu)$ from his grade and then dividing by the standard deviation $(\sigma)$ $ { z = \dfrac{x - {\mu}}{{\sigma}}} $ $ { z = \dfrac{61 - {68}}{{3.0}}} $ ${ z \approx -2.33}$ The z-score is $-2.33$. In other words, Michael's score was $2.33$ standard deviations below the mean.